Anti-inflammatory drugs: new multitarget compounds to face an old problem. The dual inhibition concept

Discovery of novel NSAID hybrids as cPLA2/COX-2 dual inhibitors alleviating rheumatoid arthritis via inhibiting p38 MAPK pathway

A series of NSAIDs hybrid molecules were synthesized and characterized, and their ability to inhibit NO release in LPS-induced RAW264.7 macrophages was evaluated. Most of the compounds showed significant anti-inflammatory activity in vitro, of which (2E,6Z,9Z,12Z,15Z)-1,1,1-trifluorohenicosa-2,6,9,12,15-pentaen-2-yl 2-(4-benzoylphenyl) propanoate (VI-60) was the most optimal (IC50 = 3.85 ± 0.25 μΜ) and had no cytotoxicity. In addition, VI-60 notably reduced the production of PGE2 in LPS-stimulated RAW264.7 cells compared to ketoprofen. Futhur more, VI-60 significantly inhibited the expression of iNOS, cPLA2, and COX-2 and the phosphorylation of p38 MAPK in LPS-stimulated RAW264.7 cells. The binding of VI-60 to cPLA2 and COX-2 was directly verified by the CETSA technique. In vivo studies illustrated that VI-60 exerted an excellent therapeutic effect on adjuvant-induced arthritis in rats by regulating the balance between Th17 and Treg through inhibiting the p38 MAPK/cPLA2/COX-2/PGE2 pathway. Encouragingly, VI-60 showed a lower ulcerative potential in rats at a dose of 50 mg/kg compared to ketoprofen. In conclusion, the hybrid molecules of NSAIDs and trifluoromethyl enols are promising candidates worthy of further investigation for the treatment of inflammation, pain, and other symptoms in which cPLA2 and COX-2 play a role in their etiology.

Design and Development of COX-II Inhibitors: Current Scenario and Future Perspective

Innate inflammation beyond a threshold is a significant problem involved in cardiovascular diseases, cancer, and many other chronic conditions. Cyclooxygenase (COX) enzymes are key inflammatory markers as they catalyze prostaglandins production and are crucial for inflammation processes. While COX-I is constitutively expressed and is generally involved in "housekeeping" roles, the expression of the COX-II isoform is induced by the stimulation of different inflammatory cytokines and also promotes the further generation of pro-inflammatory cytokines and chemokines, which affect the prognosis of various diseases. Hence, COX-II is considered an important therapeutic target for drug development against inflammation-related illnesses. Several selective COX-II inhibitors with safe gastric safety profiles features that do not cause gastrointestinal complications associated with classic anti-inflammatory drugs have been developed. Nevertheless, there is mounting evidence of cardiovascular side effects from COX-II inhibitors that resulted in the withdrawal of market-approved anti-COX-II drugs. This necessitates the development of COX-II inhibitors that not only exhibit inhibit potency but also are free of side effects. Probing the scaffold diversity of known inhibitors is vital to achieving this goal. A systematic review and discussion on the scaffold diversity of COX inhibitors are still limited. To address this gap, herein we present an overview of chemical structures and inhibitory activity of different scaffolds of known COX-II inhibitors. The insights from this article could be helpful in seeding the development of next-generation COX-II inhibitors.

Phytochemicals in the treatment of inflammation-associated diseases: the journey from preclinical trials to clinical practice

Advances in biomedical research have demonstrated that inflammation and its related diseases are the greatest threat to public health. Inflammatory action is the pathological response of the body towards the external stimuli such as infections, environmental factors, and autoimmune conditions to reduce tissue damage and improve patient comfort. However, when detrimental signal-transduction pathways are activated and inflammatory mediators are released over an extended period of time, the inflammatory process continues and a mild but persistent pro-inflammatory state may develop. Numerous degenerative disorders and chronic health issues including arthritis, diabetes, obesity, cancer, and cardiovascular diseases, among others, are associated with the emergence of a low-grade inflammatory state. Though, anti-inflammatory steroidal, as well as non-steroidal drugs, are extensively used against different inflammatory conditions, they show undesirable side effects upon long-term exposure, at times, leading to life-threatening consequences. Thus, drugs targeting chronic inflammation need to be developed to achieve better therapeutic management without or with a fewer side effects. Plants have been well known for their medicinal use for thousands of years due to their pharmacologically active phytochemicals belonging to diverse chemical classes with a number of these demonstrating potent anti-inflammatory activity. Some typical examples include colchicine (alkaloid), escin (triterpenoid saponin), capsaicin (methoxy phenol), bicyclol (lignan), borneol (monoterpene), and quercetin (flavonoid). These phytochemicals often act via regulating molecular mechanisms that synergize the anti-inflammatory pathways such as increased production of anti-inflammatory cytokines or interfere with the inflammatory pathways such as to reduce the production of pro-inflammatory cytokines and other modulators to improve the underlying pathological condition. This review describes the anti-inflammatory properties of a number of biologically active compounds derived from medicinal plants, and their mechanisms of pharmacological intervention to alleviate inflammation-associated diseases. The emphasis is given to information on anti-inflammatory phytochemicals that have been evaluated at the preclinical and clinical levels. Recent trends and gaps in the development of phytochemical-based anti-inflammatory drugs have also been included.

Synthesis of a Pyridone-Based Phthalimide Fleximer and Its Characterization and Supramolecular Property Evaluation

In this study, a novel pyridone-based phthalimide fleximer, that is, ethyl 5-cyano-6-(3-(1,3-dioxoisoindolin-2-yl)propoxy)-4-(3-methoxyphenyl)-2-methylnicotinate, was synthesized, and its structure was established by the single-crystal X-ray diffraction method. The supramolecular self-assembly of the titled compound through noncovalent interactions was then investigated thoroughly. The titled compound crystallized with two symmetry-independent molecules (A and B, Z' = 2). In agreement with experimental observations, our density functional theory calculations also showed that the titled compound has a flexible motif and can occur in various conformations, including molecules A and B. The investigation of the supramolecular framework revealed that the molecules are notably bound by the nonclassical C-H···O and C-H···N hydrogen bonds and C-H···π interactions. Hirshfeld surface analysis was carried out to quantify the various intermolecular interactions. The dual anti-inflammatory activity of the tilted compound was also explored by molecular docking in the active sites of 5-LOX and COX-2 receptors, which revealed good binding affinities of -9.0 and -8.6 kcal/mol, respectively.

Comparative evaluation of anti-inflammatory activity between n-butanol fraction, leaf and stem methanolic extract obtained from Olaxpsittacorum

ETHNOPHARMACOLOGICAL RELEVANCE

Olax psittacorum (Lam.) Vahl. traditionally used by the tribal communities of 'INDIA' to heal conditions such as pain, psoriasis, mouthulcer, anemia, constipation as well as diabetes followed by scientific evidences like antipyretic, anti-inflammatory, antimicrobial, anti-viral, and anti-cancer property too.

AIM OF THE EXPERIMENT

Solvent fractionation process by using chloroform, distilled water and n-butanol has been developed to get the precipitate as a fraction (encrypted as FrAE-ISO) of leaf methanolic extract (LME) and established GC-MS and antiinflammatory evaluation. The aim was to enumerate the potency against inflammation of FrAE-ISO comparing with LME, SME (Stem methanolic extract) and Diclofenac. TLC of LME extract has been developed too for separation & evaluation of the compounds appeared as bands obtained by scraping process. The motive of the experiment was to acquire an isolate from LME that can able to show an emense anti-inflammatory action compared to LME and SME.

MATERIALS AND METHODS

Priliminary phytochemical screening upon LME, SME and FrAE-ISO preformed by the standard methods of literatures. Scrapped portions of developed TLC plate (G-254 graded silica) of LME (n-Hexane:Ethylacetate; 7.5:2.5) were introduced to GC-MS evaluation. FrAE-ISO has introduced at a minute quantity (5 and 10 mg/kg/bw) within Wister albino rats (per os) against inflammation (model: carrageenan-induced paw edema) to evaluate its potency as compared to LME (25 mg/kg/bw), SME (25 mg/kg/bw) and Diclofenac (100 mg/kg). GC-MS evaluation has been conducted in both FrAE-ISO and scrapped sections to evaluate the presence of compounds qualitatively.

RESULTS

LME and SME, qualitatively through different screening processes confirm the presence of glycosides, flavonoids, amino acids, tannins, and saponins respectively. According to the quantitative study of the extracts concerning total phenolic, flavonoid, tannin, and saponin content equivalent to gallic acid, quercetin, tannic acid, and diosgenin respectively have shown less amount of phenolic, flavonoid, and saponin content in SME (30.95, 205.33 and 30.82 mg/g extract respectively) as compared to LME (95.68, 713.33 and 66.41 mg/g extract respectively). Quantitative estimation has shown the presence of 825.27 mg of saponin equivalent to diosgenin per gram of FrAE-ISO. The GC-MS study has revealed that every section of the leaf extract has " Hexadecanoic acid, methyl ester " in common with other important compounds responsible for its potent contribution towards the anti-inflammatory property. The scrapped portions of the TLC plate having mixture of compounds but FrAE-ISO has shown a sharp peak in GC-MS (up to 34 min of run time) as well as few crystals like structures under the binocular microscope. Compact doses of FrAEISO (yield = 1.645%) i.e. 5 and 10 mg/kg body weight was able to compete with 100 mg/kg Diclofenac portraying 88%-95% inhibition respectively throughout all phases of inflammation with no-significant differences compared to standard evaluated by ANOVA (in SPSS).

CONCLUSION

Olax psittacorum (Lam.) Vahl. could be a good choice to explore its importance within the pharmacognostic field of drug development and might be a better source of herbal-derived lead compounds which can help to treat other various activities like ulcer healing or anti-anemic property etc.

Supportive Home Remedies for Orofacial Pain during the Coronavirus Disease 2019 Pandemic: Their Value and Limitations

Background

The coronavirus disease 2019 (COVID-19) pandemic has impeded access to timely dental care, and there is an urgent need for adjuvant therapies that can reduce orofacial pain in emergencies.

Aims

To provide information on the benefits and limitations of eight representative home remedies as palliative care for orofacial pain during the coronavirus disease 2019 (COVID-19) pandemic.

Methods

PubMed and Medline were electronically searched for eight home remedies for orofacial pain that can be used in COVID-19. Papers published in English in the past 30 years were considered. Among the published studies suitable for the research purpose, those in which the abstract and body text were confirmed were targeted, and duplicate studies were excluded. Finally, 86 studies were included.

Results

There is extensive and high-level scientific evidence for the application of tooth brushing and flossing, mouth rinsing with chlorhexidine, use of over-the-counter pain medication, and application of cryotherapy in emergencies. Gargling with salt water, brushing with bamboo salt, gargling with garlic juice, and oil pulling are traditional methods used for centuries. The use of natural products for orofacial pain has a significant empirical effect but has weak scientific evidence.

Conclusions

Knowing the correct application method, effects, and side effects is desirable to use these methods appropriately in emergencies. However, scientific evidence is unclear and generally lacking for home remedies to be the main treatment strategy, and there are clear limitations to their use as a single main treatment.

Novel Applications of NSAIDs: Insight and Future Perspectives in Cardiovascular, Neurodegenerative, Diabetes and Cancer Disease Therapy

Once it became clear that inflammation takes place in the modulation of different degenerative disease including neurodegenerative, cardiovascular, diabetes and cancer the researchers has started intensive programs evaluating potential role of non-steroidal anti-inflammatory drugs (NSAIDs) in the prevention or therapy of these diseases. This review discusses the novel mechanism of action of NSAIDs and its potential use in the pharmacotherapy of neurodegenerative, cardiovascular, diabetes and cancer diseases. Many different molecular and cellular factors which are not yet fully understood play an important role in the pathogenesis of inflammation, axonal damage, demyelination, atherosclerosis, carcinogenesis thus further NSAID studies for a new potential indications based on precise pharmacotherapy model are warranted since NSAIDs are a heterogeneous group of medicines with relative different pharmacokinetics and pharmacodynamics profiles. Hopefully the new data from studies will fill in the gap between experimental and clinical results and translate our knowledge into successful disease therapy.

Lipoxygenase Inhibitors as Cancer Chemopreventives: Discovery, Recent Developments and Future Perspectives

BACKGROUND

Leukotrienes (LTs) constitute a bioactive group of Polyunsaturated Fatty Acid (PUFA) metabolites molded by the enzymatic activity of lipoxygenase (LO) and have a pivotal role in inflammation and allergy. Evidence is accumulating both by in vitro cell culture experiments and animal tumor model studies in support of the direct involvement of aberrant metabolism of arachidonic acid (ACD) in the development of several types of human cancers such as lung, prostate, pancreatic and colorectal malignancies. Several independent experimental data suggest a correlation between tumoral cells viability and LO gene expression, especially, 5-lipoxygenase (5-LO). Overexpressed 5-LO cells live longer, proliferate faster, invade more effectively through extracellular matrix destruction and activate the anti-apoptotic signaling mechanisms more intensively compared to the normal counterparts. Thus, some groups of lipoxygenase inhibitors may be effective as promising chemopreventive agents.

METHODS

A structured search of bibliographic databases for peer-reviewed research literature regarding the role of LO in the pathogenesis of cancer was performed. The characteristics of screened papers were summarized and the latest advances focused on the discovery of new LO inhibitors as anticancer agents were discussed.

RESULTS

More than 180 papers were included and summarized in this review; the majority was about the newly designed and synthesized 5-LO inhibitors as anti-inflammatory and anticancer agents. The enzyme's structure, 5-LO pathway, 5-LO inhibitors structure-activity relationships as well as the correlation between these drugs and a number of most prevalent human cancers were described. In most cases, it has been emphasized that dual cyclooxygenase-2/5-lipoxygenase (COX-2/5-LO) or dual 5-lipoxygenase/microsomal prostaglandin E synthase-1 (5-LO/mPGES-1) inhibitors possess considerable inhibitory activities against their target enzymes as well as potent antiproliferative effects. Several papers disclosing 5-lipoxygenase activating protein (FLAP) antagonists as a new group of 5-LO activity regulators are also subject to this review. Also, the potential of 12-lipoxygenase (12- LO) and 15-lipoxygenase (15-LO) inhibitors as chemopreventive agents was outlined to expand the scope of new anticancer agents discovery. Some peptides and peptidomimetics with anti-LT activities were described as well. In addition, the cytotoxic effects of lipoxygenase inhibitors and their adverse effects were discussed and some novel series of natural-product-derived inhibitors of LO was also discussed in this review.

CONCLUSION

This review gives insights into the novel lipoxygenase inhibitors with anticancer activity as well as the different molecular pharmacological strategies to inhibit the enzyme effectively. The findings confirm that certain groups of LO inhibitors could act as promising chemopreventive agents.

Simple heteroaryl modifications in the 4,5-diarylisoxazol-3-carboxylic acid scaffold favorably modulates the activity as dual mPGES-1/5-LO inhibitors with in vivo efficacy

Microsomal prostaglandin E₂ synthase-1 (mPGES-1), 5-lipoxygenase (5-LO) and 5- lipoxygenase-activating protein (FLAP) are key for biosynthesis of proinflammatory lipid mediators and pharmacologically relevant drug targets. In the present study, we made an attempt to explore the role of small heteroaromatic fragments on the 4,5-diarylisoxazol-3-carboxylic acid scaffold, which are selected to interact with focused regions in the active sites of mPGES-1, 5-LO and FLAP. We report that the simple structural variations on the benzyloxyaryl side-arm of the scaffold significantly influence the selectivity against mPGES-1, 5-LO and FLAP, enabling to produce multi-target inhibitors of these protein targets, exemplified by compound 18 (IC₅₀ mPGES-1 = 0.16 µM; IC₅₀ 5-LO = 0.39 µM) with in vivo efficacy in animal model of inflammation. The computationally modeled binding structures of these new inhibitors for three targets provide clues for rational design of modified structures as multi-target inhibitors. In conclusion, the simple synthetic procedure, and the possibility of enhancing the potency of this class of inhibitors through structural modifications pave the way for further development of new multi-target inhibitors against mPGES-1, 5-LO and FLAP, with potential application as anti-inflammatory agents.

Anti-Contractile and Anti-Inflammatory Effects of Diacerein on Isolated Mouse Airways Smooth Muscle and Mouse Asthma Model

Characterized by abnormal smooth muscle contractility and airway inflammation, asthma is one of the most common airway diseases worldwide. Diacerein is a well-known anti-inflammatory drug, widely used in osteoarthritis. In current study, the innovative usage of diacerein in anti-contractile and anti-inflammatory treatment of asthma was studied. In vitro experiments including tension measurement and patch-clamp technique and in vivo experiments including establishment of mice model and measurement of respiratory resistance were applied to explore the role of diacerein in asthma. It turned out that agonist-precontracted mouse airway smooth muscle could be relaxed by diacerein via intracellular and extracellular calcium mobilization which was mediated by switched voltage-dependent L-type Ca²⁺ channels, non-selective cation channels, large-conductance Ca²⁺-activated K⁺ channel, and Na⁺/Ca²⁺ exchangers. Furthermore, diacerein could relieve bronchospasm and control airway inflammation in asthmatic mice via reduction of several inflammatory factors. Our studies elucidated the potential therapeutic property of diacerein in asthma treatment and the possible underlying mechanism. It also confirmed that new uses for already-approved drugs could be an important form of innovation.

Anti-inflammatory activity and mechanism of action of ethanolic leaf extract of Morinda lucida Benth

Background and aim

Most developing countries resort to medicinal plants for treating diseases, but few of these have scientific backing for their use. The aim of the study was to validate traditional use of Morinda lucida leaves in treating inflammation and determine the mechanism of action.

Experimental procedure

Effect of hydroethanolic leaf extract of M. lucida (HEML) on localized inflammation was evaluated using rat paw edema presented by sub-planter injections of λ-carrageenan, histamine or serotonin in separate experiments. Systemic inflammation was evaluated by lipopolysaccharide (LPS)-induced hyperthermia. Antioxidant activity of HEML was also evaluated using the free-radical scavenging assay.

Results and conclusion

No mortalities were recorded in acute toxicity assay after administering 5000 mg/kg HEML to rats. It showed very good activity against localized and systemic inflammation in inverse dose-dependent manner and caused reduction in nitric oxide and prostaglandin E−2 levels by affecting expression of inducible nitric oxide synthase, but not cyclooxygenases-2 in LPS-activated RAW 264.7 murine macrophages. HEML reduced pro-inflammatory cytokines interleukin (IL)-1β and tumor necrotic factor, but elevated levels of anti-inflammatory cytokine IL-10 in vitro. HEML contains saponins, reducing sugars, polyphenols and flavonoids and showed antioxidant activity with EC₅₀ = 0.6415 ± 0.0027 mg/ml. In conclusion, this study provides evidence that HEML possesses anti-inflammatory activity, possibly through modulation of production of early/late phase inflammation mediators.

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HEML has anti-inflammatory effect, comparable to diclofenac.

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Mechanism of action may be via minimizing levels of pro-inflammatory mediators.

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HEML reduced NO levels via inhibition of iNOS expression.

Structure-Activity Relationships of Pentacyclic Triterpenoids as Inhibitors of Cyclooxygenase and Lipoxygenase Enzymes

Pentacyclic triterpenes may be active agents and provide a rich natural resource of promising compounds for drug development. The inhibitory activities of 29 natural oleanane and ursane pentacyclic triterpenes were evaluated against four major enzymes involved in the inflammatory process: 5-LOX, 15-LOX-2, COX-1, and COX-2. It was found that 3-O-acetyl-β-boswellic acid potently inhibited human 15-LOX-2 (IC₅₀ = 12.2 ± 0.47 μM). Analysis of the structure-activity relationships revealed that the presence of a hydroxy group at position 24 was beneficial in terms of both 5-LOX and COX-1 inhibition. Notably, the introduction of a carboxylic acid group at position 30 was important for dual 5-LOX/COX inhibitory activity; furthermore, its combination with a carbonyl group at C-11 considerably increased 5-LOX inhibition. Also, the presence of an α-hydroxy group at C-2 or a carboxylic acid group at C-23 markedly suppressed the 5-LOX activity. The present findings reveal that the types and configurations of polar moieties at positions C-2, -3, -11, -24, and -30 are important structural aspects of pentacyclic triterpenes for their potential as anti-inflammatory lead compounds.

Chemical Constituents and Effect of Topical Application of Oleum Hyperici on Skin Sensitivity to Simulated Sun Exposure

Hypericum perforatum is one of the oldest and most experimentally and clinically studied herbal drugs. In this work, using HPLC/MS/MS, we investigated the chemical composition of the methanolic extract of the flowering tops of Oleum Hyperici, an ancient remedy obtained following the methodology reported in Deutsche Arzneibuch 6 (DAB). The chemical composition of Oleum Hyperici was very different from that of the crude drug, in which two new phloroglucinols were identified for the first time. The main components responsible for the activity (hyperforin and its derivatives, hypericin and its derivatives) were not found in the oil extract. The sun protection factor (SPF) for Oleum Hyperici was demonstrated to be low.

Structural insight into the optimization of ethyl 5-hydroxybenzo[g]indol-3-carboxylates and their bioisosteric analogues as 5-LO/m-PGES-1 dual inhibitors able to suppress inflammation

The release of pro-inflammatory mediators, such as prostaglandines (PGs) and leukotrienes (LTs), arising from the arachidonic acid (AA) cascade, play a crucial role in initiating, maintaining, and regulating inflammatory processes. New dual inhibitors of 5-lipoxygenase (5-LO) and microsomal prostaglandin E₂ synthase-1 (mPGES-1), that block, at the same time, the formation of PGE₂ and LTs, are currently emerged as a highly interesting drug candidates for better pharmacotherapie of inflammation-related disorders. Following our previous studies, we here performed a detailed structure-based design of benzo[g]indol-3-carboxylate derivatives, disclosing several new key factors that affect both enzyme activity. Ethyl 2-(3,4-dichlorobenzyl)-5-hydroxy-1H-benzo[g]indole-3-carboxylate (4b, RAF-01) and ethyl 2-(3,4-dichlorophenyl)-5-hydroxy-1H-benzo[g]indole-3-carboxylate (7h, RAF-02) emerged as the most active compounds of the series. Additionally, together with selected structure based analogues, both derivatives displayed significant in vivo anti-inflammatory properties. In conclusion, modeling and experimental studies lead to the discovery of new candidate compounds prone to further developments as multi-target inhibitors of the inflammatory pathway.

Synthesis of substituted fluorobenzimidazoles as inhibitors of 5-lipoxygenase and soluble epoxide hydrolase for anti-inflammatory activity

A new series of 4-((5-fluoro-6-(substituted)-1H-benzo[d]imidazol-2-ylthio)methyl)-benzoic acids 4a-o and 2-(5-fluoro-6-(substituted)-1H-benzo[d]imidazol-2-ylthio)-2-methylpropanoic acids 8a-e were synthesized, and their inhibitory potencies against soluble epoxide hydrolase (sEH) and 5-lipoxygenase (5-LOX) were investigated. These molecules were designed based on the combination of 5-LOX and sEH pharmacophores, resulting in hybrid analogs with potent sEH and 5-LOX inhibitory activity. Compound 4g showed remarkable activity with IC₅₀ values of less than 1 μM (0.9 μM) against 5-LOX, while compound 4k displayed promising activity against sEH with IC₅₀  ≤ 1 μM (0.7 μM). These compounds were evaluated for their in vivo potential using the carrageenan-induced rat paw edema assay. Based on the obtained results, the structure-activity relationship was established and a correlation between the activities was observed. Compounds 4f, 4g, 4k, 4n, and 8e showed potent anti-inflammatory activity and significant inhibition of edema (64.13, 67.39, 66.30, 65.21, and 58.69%, respectively) at a dose of 100 mg/kg, comparable to the standard drug ibuprofen (70.65%) at 3 h.

Natural products as inhibitors of prostaglandin E2 and pro-inflammatory 5-lipoxygenase-derived lipid mediator biosynthesis

Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit prostanoid formation and represent prevalent therapeutics for treatment of inflammatory disorders. However, NSAIDs are afflicted with severe side effects, which might be circumvented by more selective suppression of pro-inflammatory eicosanoid biosynthesis. This concept led to dual inhibitors of microsomal prostaglandin E₂ synthase (mPGES)-1 and 5-lipoxygenase that are crucial enzymes in the biosynthesis of pro-inflammatory prostaglandin E₂ and leukotrienes. The potential of their dual inhibition in light of superior efficacy and safety is discussed. Focus is placed on natural products, for which direct inhibition of mPGES-1 and leukotriene biosynthesis has been confirmed.

Common structural and pharmacophoric features of mPGES-1 and LTC4S

Prostaglandins and leukotrienes are produced in the COX and 5-LOX pathways of the inflammatory process. The current drugs target the upstream enzymes of either of the two pathways, leading to side effects. We have attempted to target the downstream enzymes simultaneously. Two compounds 2 and 3 (10 μM), identified by virtual screening, inhibited mPGES-1 activity by 53.4 ± 4.0 and 53.9 ± 8.1%, respectively. Structural and pharmacophore studies revealed a set of common residues between LTC4S and mPGES-1 as well as four-point pharmacophore mapping onto the inhibitors of both these enzymes as well as 2 and 3. These structural and pharmacophoric features may be exploited for ligand- and structure-based screening of inhibitors and designing of dual inhibitors.

New selective cyclooxygenase-2 inhibitors from cyclocoumarol: Synthesis, characterization, biological evaluation and molecular modeling

In this work, a serie of cyclocoumarol derivatives was designed, synthesized, characterized and studied for their potentialities as selective inhibitors of COX-2. All target compounds have been screened for their anti-inflammatory activity by the assay of PGE₂ production. Among them, compound 5d exhibited the most potent inhibitory activity with a PGE₂ inhibition compared to NS-398 (79% and 88% respectively) and showed non-inhibitory activity towards the COX-1 enzyme. Docking studies revealed the capacity of this compound to occupy the selective COX-2 cavity establishing additional hydrogen bonds between the oxygen of the methoxy group and the His90 and Arg513 of the binding site of the enzyme.

Ligand-based Modeling for the Prediction of Pharmacophore Features for Multi-targeted Inhibition of the Arachidonic Acid Cascade

The single-target drugs against the arachidonic acid inflammatory pathway are associated with serious side effects, hence, as a first step towards multi-target drugs, we have studied the pharmacophoric features common to the inhibitors of 5-lipoxygenase-activating protein (FLAP), microsomal prostaglandin E-synthase 1 (mPGES-1) and leukotriene A4 hydrolase (LTA4H). FLAP and mPGES-1 shared subfamily-specific positions (SSPs) and four mPGES-1 inhibitors binding to them mapped onto the pharmacophore derived from FLAP inhibitors (Ph-FLAP). The reactions of mPGES-1 and LTA4H had high structural similarity. The pharmacophore derived from two substrate mimic inhibitors of LTA4H (Ph-LTA4H) also mapped onto three mPGES-1 inhibitors. Screening of in-house database for Ph-FLAP and Ph-LTA4H identified one compound, C1. It inhibited the production of the mPGES-1 product, prostaglandin E2 (PGE2) by 97.8±1.6 % at 50 μM in HeLa cells and can be a starting point for designing molecules inhibiting all three targets simultaneously.

Pharmacological profile and efficiency in vivo of diflapolin, the first dual inhibitor of 5-lipoxygenase-activating protein and soluble epoxide hydrolase

Arachidonic acid (AA) is metabolized to diverse bioactive lipid mediators. Whereas the 5-lipoxygenase-activating protein (FLAP) facilitates AA conversion by 5-lipoxygenase (5-LOX) to pro-inflammatory leukotrienes (LTs), the soluble epoxide hydrolase (sEH) degrades anti-inflammatory epoxyeicosatrienoic acids (EETs). Accordingly, dual FLAP/sEH inhibition might be advantageous drugs for intervention of inflammation. We present the in vivo pharmacological profile and efficiency of N-[4-(benzothiazol-2-ylmethoxy)-2-methylphenyl]-N′-(3,4-dichlorophenyl)urea (diflapolin) that dually targets FLAP and sEH. Diflapolin inhibited 5-LOX product formation in intact human monocytes and neutrophils with IC₅₀ = 30 and 170 nM, respectively, and suppressed the activity of isolated sEH (IC₅₀ = 20 nM). Characteristic for FLAP inhibitors, diflapolin (I) failed to inhibit isolated 5-LOX, (II) blocked 5-LOX product formation in HEK cells only when 5-LOX/FLAP was co-expressed, (III) lost potency in intact cells when exogenous AA was supplied, and (IV) prevented 5-LOX/FLAP complex assembly in leukocytes. Diflapolin showed target specificity, as other enzymes related to AA metabolism (i.e., COX1/2, 12/15-LOX, LTA₄H, LTC₄S, mPGES₁, and cPLA₂) were not inhibited. In the zymosan-induced mouse peritonitis model, diflapolin impaired vascular permeability, inhibited cysteinyl-LTs and LTB₄ formation, and suppressed neutrophil infiltration. Diflapolin is a highly active dual FLAP/sEH inhibitor in vitro and in vivo with target specificity to treat inflammation-related diseases.

Gastrointestinal toxicity among patients taking selective COX-2 inhibitors or conventional NSAIDs, alone or combined with proton pump inhibitors: a case-control study

PURPOSE

To assess the risk of gastrointestinal perforation, ulcers, or bleeding (PUB) associated with the use of conventional nonsteroidal anti-inflammatory drugs (NSAIDs) with proton pump inhibitors (PPIs) and selective COX-2 inhibitors, with or without PPIs compared with conventional NSAIDs.

METHODS

A case-control study was performed within conventional NSAIDs and/or selective COX-2 inhibitors users identified from the Dutch PHARMO Record Linkage System in the period 1998-2012. Cases were patients aged ≥18 years with a first hospital admission for PUB. For each case, up to four controls were matched for age and sex at the date a case was hospitalized (index date). Logistic regression analysis was used to calculate odds ratios (ORs).

RESULTS

At the index date, 2634 cases and 5074 controls were current users of conventional NSAIDs or selective COX-2 inhibitors. Compared with conventional NSAIDs, selective COX-2 inhibitors with PPIs had the lowest risk of PUB (adjusted OR 0.51, 95% confidence interval [CI]: 0.35-0.73) followed by selective COX-2 inhibitors (adjusted OR 0.66, 95%CI: 0.48-0.89) and conventional NSAIDs with PPIs (adjusted OR 0.79, 95%CI: 0.68-0.92). Compared with conventional NSAIDs, the risk of PUB was lower for those aged ≥75 years taking conventional NSAIDs with PPIs compared with younger patients (adjusted interaction OR 0.79, 95%CI: 0.64-0.99). However, those aged ≥75 years taking selective COX-2 inhibitors, the risk was higher compared with younger patients (adjusted interaction OR 1.22, 95%CI: 1.01-1.47).

CONCLUSIONS

Selective COX-2 inhibitors with PPIs, selective COX-2 inhibitors, and conventional NSAIDs with PPIs were associated with lower risks of PUB compared with conventional NSAIDs. These effects were modified by age. © 2017 The Authors. Pharmacoepidemiology & Drug Safety Published by John Wiley & Sons Ltd.

In Silico Analysis of the Potential of the Active Compounds Fucoidan and Alginate Derived from Sargassum Sp. as Inhibitors of COX-1 and COX-2

INTRODUCTION

The enzyme cyclooxygenase (COX) is an enzyme that catalyzes the formation of one of the mediators of inflammation, the prostaglandins. Inhibition of COX allegedly can improve inflammation-induced pathological conditions.

AIM

The purpose of the present study was to evaluate the potential of Sargassum sp. components, Fucoidan and alginate, as COX inhibitors.

MATERIAL AND METHODS

The study was conducted by means of a computational (in silico) method. It was performed in two main stages, the docking between COX-1 and COX-2 with Fucoidan, alginate and aspirin (for comparison) and the analysis of the amount of interactions formed and the residues directly involved in the process of interaction.

RESULTS

Our results showed that both Fucoidan and alginate had an excellent potential as inhibitors of COX-1 and COX-2. Fucoidan had a better potential as an inhibitor of COX than alginate. COX inhibition was expected to provide a more favorable effect on inflammation-related pathological conditions.

CONCLUSION

The active compounds Fucoidan and alginate derived from Sargassum sp. were suspected to possess a good potential as inhibitors of COX-1 and COX-2.

Analgesic potential of standardized methanol stem bark extract of Ficus platyphylla in mice: Mechanisms of action

ETHNOPHARMACOLOGICAL RELEVANCE

Extracts of the stem bark of Ficus platyphylla (FP) have been used in traditional the Nigerian medicine to treat psychoses, depression, epilepsy, pain and inflammation. Previous studies have revealed the analgesic and anti-inflammatory effects of FP in different assays including acetic acid-induced writhing, formalin-induced nociception, and albumin-induced oedema.

PURPOSE/METHODS

In this study, we assessed the effects of the standardised extract of FP on hot plate nociceptive threshold and vocalisation threshold in response to electrical stimulation of the tail root in order to confirm its acclaimed analgesic properties. We also investigated the molecular mechanisms underlying these effects, with the focus on opiate receptor binding and the key enzymes of eicosanoid biosynthesis, namely cyclooxygenase (COX) and 5-lipoxygenase (5-LO).

RESULTS

FP (i) increased the hot plate nociceptive threshold and vocalisation threshold. The increase in hot plate nociceptive threshold was detectable over a period of 30min whereas the increase in vocalisation threshold persisted over a period of 90min. (ii) FP showed an affinity for µ opiate receptors but not for δ or κ opiate receptors, and (iii) FP inhibited the activities of COX-2 and 5-LO but not of COX-1.

CONCLUSIONS

We provided evidence supporting the use of FP in Nigerian folk medicine for the treatment of different types of pain, and identified opioid and non-opioid targets. It is interesting to note that the dual inhibition of COX-2 and 5-LO appears favourable in terms of both efficacy and side effect profile.

The inhibitory activity of cocoa phenolic extract against pro-inflammatory mediators secretion induced by lipopolysaccharide in RAW 264.7 cells

Cocoa is a rich source of polyphenols that has been traditionally used as the treatment of several types of inflammation related disease. The response to inflammation comprises the consecutive release of mediators and the enlistment of circulating leukocytes, such as macrophages. Currently, Cocoa-derived polyphenolics have shown anti-inflammatory effects in vivo, but the therapeutic benefits in vitro remain unclear. Therefore, in this study, the effect of cocoa polyphenolic extract (CPE) on RAW 264.7 macrophage cells sensitized by lipopolysaccharide as in vitro inflammatory model was investigated. The anti-inflammatory activity of CPE was assessed by measuring its ability to inhibit the pro-inflammatory enzyme 5-lipoxygenase (5-LOX) and the pro-inflammatory mediators prostaglandin E₂ (PGE₂), reactive oxygen species (ROS), nitric oxide (NO) and tumor necrosis factor-alpha (TNF-α). The results show that CPE significantly inhibits 5-LOX activity (p < 0.01). In addition, CPE dose-dependently suppressed the production of PGE₂, ROS, NO and TNF-α in RAW 264.7 cells. These data suggest that CPE may be used for the treatment of inflammation and it’s related-diseases.

Perspective of microsomal prostaglandin E2 synthase-1 as drug target in inflammation-related disorders

Prostaglandin (PG)E2 encompasses crucial roles in pain, fever, inflammation and diseases with inflammatory component, such as cancer, but is also essential for gastric, renal, cardiovascular and immune homeostasis. Cyclooxygenases (COX) convert arachidonic acid to the intermediate PGH2 which is isomerized to PGE2 by at least three different PGE2 synthases. Inhibitors of COX - non-steroidal anti-inflammatory drugs (NSAIDs) - are currently the only available therapeutics that target PGE2 biosynthesis. Due to adverse effects of COX inhibitors on the cardiovascular system (COX-2-selective), stomach and kidney (COX-1/2-unselective), novel pharmacological strategies are in demand. The inducible microsomal PGE2 synthase (mPGES)-1 is considered mainly responsible for the excessive PGE2 synthesis during inflammation and was suggested as promising drug target for suppressing PGE2 biosynthesis. However, 15 years after intensive research on the biology and pharmacology of mPGES-1, the therapeutic value of mPGES-1 as drug target is still vague and mPGES-1 inhibitors did not enter the market so far. This commentary will first shed light on the structure, mechanism and regulation of mPGES-1 and will then discuss its biological function and the consequence of its inhibition for the dynamic network of eicosanoids. Moreover, we (i) present current strategies for interfering with mPGES-1-mediated PGE2 synthesis, (ii) summarize bioanalytical approaches for mPGES-1 drug discovery and (iii) describe preclinical test systems for the characterization of mPGES-1 inhibitors. The pharmacological potential of selective mPGES-1 inhibitor classes as well as dual mPGES-1/5-lipoxygenase inhibitors is reviewed and pitfalls in their development, including species discrepancies and loss of in vivo activity, are discussed.

Omega-3 polyunsaturated fatty acids as an angelus custos to rescue patients from NSAID-induced gastroduodenal damage

Nonsteroidal anti-inflammat ory drugs (NSAIDs) are one of the drug types frequently prescribed for their analgesic, anti-inflammatory, and antithrombotic actions, but carry a risk of major gastroduodenal damage from mild erosive changes to serious ulceration leading to fatal outcomes. From the long history of willow tree bark and its extracts being applied for the relief of pain and fever, the synthesis of acetylsalicylic acid, the development of selective cyclooxygenase 2 inhibitors (coxibs), and the identification of a G-protein-coupled receptor for prostaglandin, the popular combination regimen of an NSAID and a proton pump inhibitor was invented, but development was continued for further improvement. With regard to major NSAID adverse effects, gastrointestinal (GI) and cardiovascular (CV) risks still remained as problems to be solved. In this review, it is shown that n-3 polyunsaturated fatty acid (PUFA) based NSAIDs can be an angelus custos, supported with facts that an intake of essential n-3 PUFAs orchestrates concerted protective actions against two notorious side effects of NSAIDs, the aforementioned GI risk and CV risk of NSAIDs. Since pills containing n-3 PUFAs, omega-3-acid ethyl ester capsules (Lovaza, Omarcor), have already been safely prescribed to prevent atherosclerosis through lessening lipid burdening, the introduction of a drug delivery system such as a gastroretentive form of n-3 PUFA based NSAIDs will highlight newer hope for GI safety under the guarantee of reduced CV risk. Because n-3 PUFAs have been proven to attenuate cytotoxicity, inhibit lipid-raft-associated harmful signaling, and relieve oxidative stress relevant to NSAIDs, n-3 PUFA based NSAIDs will be next-generation GI-safe NSAIDs.

Synthesis, analgesic and anti-inflammatory activities of new methyl-imidazolyl-1,3,4-oxadiazoles and 1,2,4-triazoles

Background

Long-term clinical employment of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with significant side effects including gastrointestinal (GI) lesions and kidney toxicity. In this paper we designed and synthesized new imidazolyl-1,3,4-oxadiazoles and 1,2,4-triazoles by molecular hybridization of previously described anti-inflammatory compounds in the hope of obtaining new safer analgesic and anti-inflammatory agents.

Methods

The target structures were synthesized by preparation of 5-methyl-1H-imidazole-4-carboxylic acid ethyl ester 5. The reaction of hydrazine hydrate with this ester afforded the 5-methyl-1H-imidazole-4-carboxylic acid hydrazide 6 which was converted to target compounds 7-15 according to the known procedures. In silico toxicity risk assessment and drug likeness predictions were done, in order to consider the privileges of the synthesized structures as drug candidates.

Results and discussion

The analgesic and anti-inflammatory profile of the synthesized compounds were evaluated by writhing and carrageenan induced rat paw edema tests respectively. Compounds 8, 9 and 11-13 and 15 were active analgesic agents and compounds 8, 9 and 11-13 showed significant anti-inflammatory response in comparison with control. Compounds 11 and 13 were screened for their ulcerogenic activities and none of them showed significant ulcerogenic activity. The active Compounds 11 and 12 showed the highest drug likeness and drug score.

Conclusions

The analgesic and anti-inflammatory activities of title compounds were comparable to that of standard drug indomethacin with a safer profile of activity. The results revealed that both of oxadiazole and triazole scaffolds can be determined as pharmacophores. The in silico predictions and pharmacological evaluations showed that compounds 11 and 12 can be chosen as lead for further investigations.

Defibrotide: properties and clinical use of an old/new drug

The drug named defibrotide (DFT) has been studied for many years. It has been shown to possess many activities: profibrinolytic, antithrombotic-thrombolytic, antiischemic (heart, liver, kidney, skin, brain), antishock, antiatherosclerotic, antirejection and anti-angiogenic. The previously displayed activities, as antithrombotic, profibrinolytic and anti-inflammatory, suggested its use in vascular disorders, as in the treatment of peripheral obliterative arterial disease and in thrombophlebitis. Some years after, the use of DFT in hepatic veno-occlusive disease has been also proposed. Even if DFT was considered for long time a multi-target drug, now it could be considered on the whole as a drug able to protect endothelium against activation. The present work reviews the more important experimental and clinical studies performed to detect DFT effects.

Toxicological, toxicokinetic and gastroprotective evaluation of the benzaldehyde semicarbazone

Benzaldehyde semicarbazone (BS) has presented positive results in several pharmacological models, including anticonvulsivant and anti-inflammatory models. The present study evaluated the preclinical toxicity (acute and subchronic), as well as the toxicokinetic and gastroprotective effects of BS against ethanol lesions. Oral doses of 300 and 2000mg/kg were used in the preclinical acute toxicity study; 100, 200, and 300mg/kg were used in both the subchronic toxicity evaluation and the gastric study; and 300mg/kg was used in the toxicokinetic study. No impact from the dose of 300mg/kg could be identified; while, one animal died at 2000mg/kg in the acute toxicity test. In the subchronic toxicity test, changes in the biochemical parameters of the liver, as well as in the histopatological evaluation, demonstrated that BS is a hepatotoxic drug. BS proved to be effective for moderate and severe gastric lesions. In the toxicokinetics study, BS presented a low concentration and rapid plasma disappearance. Several results also indicate that BS is likely to be mostly eliminated from the liver and may well undergo a first-pass effect after oral absorption. It was impossible to estimate the noobserved-adverse-effect-levels (NOAEL) and lowest-observed-adverse-effect-levels (LOAEL) due to the presence of hepatotoxicity in all tested doses.

Microsomal Prostaglandin E2 Synthase-1

The prostanoids and leukotrienes (LTs) formed from arachidonic acid (AA) via the cyclooxygenase (COX)-1/2 and 5-lipoxygenase (5-LO) pathway, respectively, mediate inflammatory responses, chronic tissue remodelling, cancer, asthma and autoimmune disorders, but also possess homeostatic functions in the gastrointestinal tract, uterus, brain, kidney, vasculature and host defence. Based on the manifold functions of these eicosanoids, the clinical use of non-steroidal anti-inflammatory drugs (NSAIDs), a class of drugs that block formation of all prostanoids, is hampered by severe side-effects including gastrointestinal injury, renal irritations and cardiovascular risks. Therefore, anti-inflammatory agents interfering with eicosanoid biosynthesis require a well-balanced pharmacological profile to minimize these on-target side-effects. Current anti-inflammatory research aims at identifying compounds that can suppress the massive formation of pro-inflammatory prostaglandin (PG)E2 without affecting homeostatic PGE2 and PGI2 synthesis. The inducible microsomal prostaglandin E2 synthase-1 (mPGES-1) is one promising target enzyme. We will give an overview about the structure, regulation and function of mPGES-1 and then present novel inhibitors of mPGES-1 that may possess a promising pharmacological profile.

The Gastroprotective Role of Acanthus ilicifolius - A Study to Unravel the Underlying Mechanism of Anti-Ulcer Activity

Acanthus ilicifolius (Acanthaceae), a mangrove medicinal plant, is widely used by the local inhabitants of the Sundarbans (India) to treat a variety of diseases. As a part of our continued search for novel bioactive products from mangrove medicinal plants, we were able to document the anti-inflammatory effects of this plant. In the present study, we have performed a detailed evaluation of the gastroprotective activity of the methanolic extract of Acanthus ilicifolius using different models of gastric ulceration. Unlike the conventional non-steroidal anti-inflammatory drugs, a methanolic extract of Acanthus ilicifolius leaves (MEAL) possessing significant anti-inflammatory properties, as revealed from our previous studies displayed in rats in dosages of 200 mg and 400 mg/kg BW after intraperitoneal administration, showed significant protective activity (anti-ulcer activity) against the gastric lesions induced by aspirin, indomethacin, stress, ethanol, and pylorus ligation. In pylorus-ligated rats, administration of Methanolic extract of Acanthus ilicifolius leaves (MEAL) significantly decreased gastric volume, acidity, and peptic activity. Moreover, pre-treatment with MEAL significantly restored the levels of reduced glutathione (GSH) and the antioxidant enzyme superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX), along with significant inhibition of both lipid peroxidation and myeloperoxidase (MPO) activity in pylorus-ligated animals. Ulceration induced with ethanol was significantly inhibited with MEAL, and the extract also resulted in the reduction of both lipid peroxidation and myeloperoxidase activity. Furthermore, in this experimental model, administration of MEAL improved the activities of SOD, CAT, GSH, and GPX. A similar pattern of action was also noticed in cold-restraint stress-induced (CRS) ulceration, where MEAL pre-treatment inhibited CRS-induced ulceration, improved the status of antioxidant enzymes, and also reduced the level of lipid peroxides. These results suggest that extracts of the leaves of Acanthus ilicifolius may exhibit anti-ulcer activities additional to the anti-inflammatory properties.

Efficient synthesis and 5-LOX/COX-inhibitory activity of some 3-hydroxybenzo[b]thiophene-2-carboxylic acid derivatives

A series of 3-hydroxybenzo[b]thiophene-2-carboxylic acid derivatives has been prepared and subsequently evaluated with regards to the inhibition of 5-LOX/COX. Structure optimization furnished derivatives with promising in vitro activity as dual 5-LOX/COX inhibitors with submicromolar IC(50) values for inhibition of 5-LOX and COX-1, respectively.

Ethnopharmacological study of plants from Pondoland used against diarrhoea

ETHNOPHARMACOLOGICAL RELEVANCE

Waterborne diseases such as diarrhoea are common world wide, including in Bizana, South Africa where the majority of rural dwellers depend largely on water from unprotected sources. The people from Bizana use medicinal plants as their first line of health care to cure and prevent diarrhoea.

AIM OF THE STUDY

To record and document plants used for the treatment of diarrhoea in Bizana, to evaluate antibacterial and anti-inflammatory activities of selected plant extracts as well as to perform genotoxicity testing of evaluated plants.

MATERIALS AND METHODS

An ethnobotanical approach was used to select plants used for treating diarrhoea in Bizana for pharmacological assays using questionnaires. Nine plants were selected for bioassays based on their frequency index and the fact that they have never been evaluated against diarrhoea causing-microorganisms. The petroleum ether (PE), dichloromethane (DCM), 70% ethanol (EtOH), and water extracts were evaluated for antibacterial (Gram-positive Staphylococcus aureus, Gram-negative Escherichia coli and Shigella flexneri) activity using the microdilution technique, their ability to inhibit COX-1 and COX-2 enzymes. Genotoxicity was evaluated using the Salmonella microsome assay.

RESULTS

This study revealed that 34 plant species belonging to 27 families are used for the treatment of diarrhoea in Bizana. The extracts showed good inhibitory activity with MIC values ranging from 0.39 to 12.5mg/ml. The best activity was exhibited by DCM extracts of Rapanea melanophloeos, and EtOH extracts of Ficus craterostoma and Maesa lanceolata with MIC values of 0.098mg/ml. The inhibitory activity against COX-1 enzyme was higher than COX-2, with 19 plant extracts for the former and 7 for the latter. All the tested plant extracts were not mutagenic at all concentrations tested against all tester strains of bacteria.

CONCLUSION

In view of the fact that the plants were selected based on their ethnobotanical usage for treating diarrhoea, the activities reported here goes a long way in validating the plants for traditional use.

Carnosol and carnosic acids from Salvia officinalis inhibit microsomal prostaglandin E2 synthase-1

Prostaglandin E(2) (PGE(2)), the most relevant eicosanoid promoting inflammation and tumorigenesis, is formed by cyclooxygenases (COXs) and PGE(2) synthases from free arachidonic acid. Preparations of the leaves of Salvia officinalis are commonly used in folk medicine as an effective antiseptic and anti-inflammatory remedy and possess anticancer activity. Here, we demonstrate that a standard ethyl acetate extract of S. officinalis efficiently suppresses the formation of PGE(2) in a cell-free assay by direct interference with microsomal PGE(2) synthase (mPGES)-1. Bioactivity-guided fractionation of the extract yielded closely related fractions that potently suppressed mPGES-1 with IC(50) values between 1.9 and 3.5 μg/ml. Component analysis of these fractions revealed the diterpenes carnosol and carnosic acid as potential bioactive principles inhibiting mPGES-1 activity with IC(50) values of 5.0 μM. Using a human whole-blood assay as a robust cell-based model, carnosic acid, but not carnosol, blocked PGE(2) generation upon stimulation with lipopolysaccharide (IC(50) = 9.3 μM). Carnosic acid neither inhibited the concomitant biosynthesis of other prostanoids [6-keto PGF(1α), 12(S)-hydroxy-5-cis-8,10-trans-heptadecatrienoic acid, and thromboxane B(2)] in human whole blood nor affected the activities of COX-1/2 in a cell-free assay. Together, S. officinalis extracts and its ingredients carnosol and carnosic acid inhibit PGE(2) formation by selectively targeting mPGES-1. We conclude that the inhibitory effect of carnosic acid on PGE(2) formation, observed in the physiologically relevant whole-blood model, may critically contribute to the anti-inflammatory and anticarcinogenic properties of S. officinalis.

Flavocoxid, a dual inhibitor of COX-2 and 5-LOX of natural origin, attenuates the inflammatory response and protects mice from sepsis

INTRODUCTION

Cecal ligation and puncture (CLP) is an inflammatory condition that leads to multisystemic organ failure. Flavocoxid, a dual inhibitor of cyclooxygenase (COX-2) and 5-lipoxygenase (5-LOX), has been shown in vitro to possess antiinflammatory activity in lipopolysaccharide (LPS)-stimulated rat macrophages by reducing nuclear factor (NF)-κB activity and COX-2, 5-LOX and inducible nitric oxide synthase (iNOS) expression. The aim of this study was to evaluate the effects of flavocoxid in a murine model of CLP-induced polymicrobial sepsis.

METHODS

C57BL/6J mice were subjected to CLP or sham operation. In a first set of experiments, an intraperitoneal injection of flavocoxid (20 mg/kg) or vehicle was administered 1 hour after surgery and repeated every 12 hours. Survival rate was monitored every 24 hours throughout 120 hours. Furthermore, additional groups of sham and CLP mice were killed 18 hours after surgical procedures for blood-sample collection and the lung and liver were collected for biomolecular, biochemical and histopathologic studies.

RESULTS

COX-2, 5-LOX, tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-10, extracellular-regulated-kinase 1/2 (ERK), JunN-terminal kinase (JNK), NF-κB, and β-arrestin 2 protein expression were evaluated in lung and liver with Western blot analysis. In addition, leukotriene B4 (LTB4), prostaglandin E2 (PGE2), cytokines, and lipoxin A4 serum content were measured with an enzyme-linked immunosorbent assay (ELISA). Flavocoxid administration improved survival, reduced the expression of NF-κB, COX-2, 5-LOX, TNF-α and IL-6 and increased IL-10 production. Moreover, flavocoxid inhibited the mitogen-activated protein kinases (MAPKs) pathway, preserved β-arrestin 2 expression, reduced blood LTB4, PGE2, TNF-α and IL-6, and increased IL-10 and lipoxin A4 serum levels. The treatment with flavocoxid also protected against the histologic damage induced by CLP and reduced the myeloperoxidase (MPO) activity in the lung and liver.

CONCLUSIONS

Flavocoxid protects mice from sepsis, suggesting that this dual inhibitor may represent a promising approach in such a life-threatening condition.

Effects of typheramide and alfrutamide found in Allium species on cyclooxygenases and lipoxygenases

Typheramide (N-caffeoyltyramine) and alfrutamide (N-feruloyltyramine) are phenylpropenoic acid amides found in plants. In this article, typheramide and alfrutamide were isolated from Allium sativum (garlic) and Allium fistulosum (green onion), their chemical structures were confirmed using nuclear magnetic resonance spectroscopic methods, and the potential effects on cyclooxygenases (COXs) (COX 1 and 2) and lipoxygenases (LOXs) (5- and 15-LOX) were investigated. Typheramide and alfrutamide inhibited COX 1 by 74% (P < .01) and 60% (P < .01), respectively, at the concentration of 0.1 μM; at the same concentration, they also inhibited COX 2 by 68% (P < .02) and 54% (P < .02), respectively. Typheramide was slightly stronger than alfrutamide in inhibiting COX enzymes, and the inhibition patterns of COX 1 and 2 were uncompetitive with K(i) = 0.032 and 0.047 μM, respectively. However, typheramide and alfrutamide were not able to inhibit 5-LOX, and they only moderately inhibited 15-LOX by 27% (P < .02) and 17% (P < .02), respectively, at the relatively high concentration of 25 μM. Altogether, the data suggest that typheramide and alfrutamide from garlic and green onions are likely to be significant inhibitors for COX 1 and 2 rather than 5- and 12-LOX.